Magento: The admin category form is not displayed.

Question

I am working on a magento project and have some problems with it, I searched a lot on the net but did not find anything related to it.

1) under admin> catalog> the category of categories of categories of categories of categories is not displayed, it is displayed for a second and then disappears when fully loaded.
2) I used firebug to see if there is any data under html, but it is deleted after loading.
3) Ajax is not part of the admin firebug console.
4) I have the ajax post url from the NET firebug tab, and then another tab is open and the answer is found.
5) when you click on the left bar, the parent categories plus the child’s sign also do not load
6) Any category does not load ...

Please help if someone has some previous experience or guess what is happening.

Updated error screen for chrome

Answer 1

Given that both screen captures indicate that one or more indexes are out of date. Start with those.

Then delete these folders, /var/cache /var/session /var/full_page_cache (under the root of Magento) you will need to log in by deleting /var/session

Disable all recently installed extensions or modifications.

Answer 2

You need to do basic debugging to answer this question. Turn on the error log and check it for errors on the page, this, I hope, will give you an error message if you do not already have it. Check System Log

If you have any new modules, temporarily remove them. Go back to the old version of the code that works, and then see what has changed between the two versions.

Try increasing PHP memory_limit and ticking once.